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A249435
a(1) = 0, after which one less than prime powers p^m with exponent m >= 2.
3
0, 3, 7, 8, 15, 24, 26, 31, 48, 63, 80, 120, 124, 127, 168, 242, 255, 288, 342, 360, 511, 528, 624, 728, 840, 960, 1023, 1330, 1368, 1680, 1848, 2047, 2186, 2196, 2208, 2400, 2808, 3124, 3480, 3720, 4095, 4488, 4912, 5040, 5328, 6240, 6560, 6858, 6888, 7920, 8191, 9408, 10200, 10608, 11448
OFFSET
1,2
LINKS
Charles R Greathouse IV, Table of n, a(n) for n = 1..10000
FORMULA
a(n) = A025475(n) - 1.
PROG
(Scheme) (define (A249435 n) (- (A025475 n) 1))
(PARI) list(lim)=my(v=List([0])); lim=lim\1+1; for(m=2, logint(lim, 2), forprime(p=2, sqrtnint(lim, m), listput(v, p^m-1))); Set(v) \\ Charles R Greathouse IV, Aug 26 2015
CROSSREFS
One less than A025475.
Subsequence of A181062 and also a subsequence of A249433 (after the initial zero).
Union of sequences A000225, A024023, A024049, A024075, A024127, etc. without their term a(1).
Apart from the first term, subsequence of A045542.
Sequence in context: A309197 A076683 A045542 * A192120 A031404 A263519
KEYWORD
nonn
AUTHOR
Antti Karttunen, Nov 02 2014
STATUS
approved